Scaphites
Encyclopedia
Scaphites is a genus
of extinct cephalopod
belonging to the family of heteromorph ammonite
s (suborder Ancyloceratina
). They were a widespread genus that thrived during the Cretaceous
period.
Scaphites generally have a chambered, boat-shaped shell. The initial part (juvenile stage) of the shell is generally more or less involute (tightly-coiled) and compressed, giving no hint of the heteromorphic shell form yet to come. The terminal part (adult stage) is much shorter, erect, and bends over the older shell like a hook. They have transverse, branching ribs with tubercles (small bumps) along the venter.
Reconstructions of the body within the shell can be made to portray Scaphites as either a benthic (bottom-dwelling) or plankton
ic animal, depending on where the center of gravity is located. Since useful fossil
s of the soft-body parts of cephalopods are highly rare, little is known about how this animal actually fit into its shell and lived its life.
Because Scaphites and its relatives in Superfamily Scaphitaceae are restricted to certain divisions of the Cretaceous
(ca. 144 to 66.4 million years ago), they are useful in some areas as an index fossil
. A notable example is the Late Cretaceous Western Interior Seaway
in North America, in which several endemic
lineages of scaphite species evolved and now serve as the basis for a highly resolved regional biostratigraphy
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of extinct cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
belonging to the family of heteromorph ammonite
Ammonite
Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct subclass within the Molluscan class Cephalopoda which are more closely related to living coleoids Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct...
s (suborder Ancyloceratina
Ancyloceratina
The Ancyloceratina were a diverse suborder of ammonite most closely related to the ammonites of order Lytoceratina. They evolved during the Late Jurassic but were not very common until the Cretaceous period, when they rapidly diversified and become one of the most distinctive components of...
). They were a widespread genus that thrived during the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period.
Scaphites generally have a chambered, boat-shaped shell. The initial part (juvenile stage) of the shell is generally more or less involute (tightly-coiled) and compressed, giving no hint of the heteromorphic shell form yet to come. The terminal part (adult stage) is much shorter, erect, and bends over the older shell like a hook. They have transverse, branching ribs with tubercles (small bumps) along the venter.
Reconstructions of the body within the shell can be made to portray Scaphites as either a benthic (bottom-dwelling) or plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
ic animal, depending on where the center of gravity is located. Since useful fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of the soft-body parts of cephalopods are highly rare, little is known about how this animal actually fit into its shell and lived its life.
Because Scaphites and its relatives in Superfamily Scaphitaceae are restricted to certain divisions of the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
(ca. 144 to 66.4 million years ago), they are useful in some areas as an index fossil
Index fossil
Index fossils are fossils used to define and identify geologic periods . They work on the premise that, although different sediments may look different depending on the conditions under which they were laid down, they may include the remains of the same species of fossil...
. A notable example is the Late Cretaceous Western Interior Seaway
Western Interior Seaway
The Western Interior Seaway, also called the Cretaceous Seaway, the Niobraran Sea, and the North American Inland Sea, was a huge inland sea that split the continent of North America into two halves, Laramidia and Appalachia, during most of the mid- and late-Cretaceous Period...
in North America, in which several endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
lineages of scaphite species evolved and now serve as the basis for a highly resolved regional biostratigraphy
Biostratigraphy
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them. Usually the aim is correlation, demonstrating that a particular horizon in one geological section represents the same period...
.
Species
- Scaphites binneyi † Reeside 1927a
- Scaphites carlilensis † Morrow 1935
- Scaphites depressus † Reeside 1927a
- Scaphites ferronensis † Cobban, 1951b
- Scaphites frontierensis † Cobban 1951b
- Scaphites hippocrepis † (DeKayJames Ellsworth De KayJames Ellsworth De Kay was an American zoologist.-Biography:...
) 1827 - Scaphites impendicostatus † Cobban 1951b
- Scaphites leei † Reeside 1927b
- Scaphites nanus † Reeside 1927b
- Scaphites nodosus †
- Scaphites obliquus † J. SowerbyJames SowerbyJames Sowerby was an English naturalist and illustrator. Contributions to published works, such as A Specimen of the Botany of New Holland or English Botany, include his detailed and appealing plates...
1813 - Scaphites preventricosus † Cobban 1951b
- Scaphites tetonensis † Cobban 1951b
- Scaphites uintensis † Cobban 1951b
- Scaphites warreni † MeekFielding Bradford MeekFielding Bradford Meek was an American geologist and paleontologist.The son of a lawyer, he was born in Madison, Indiana. In early life he was in business as a merchant, but his leisure hours were devoted to collecting fossils and studying the rocks of the neighborhood of Madison...
and HaydenFerdinand Vandeveer HaydenDr. Ferdinand Vandeveer Hayden was an American geologist noted for his pioneering surveying expeditions of the Rocky Mountains in the late 19th century. He was also a physician who served with the Union Army during the Civil War.-Early life:Ferdinand Hayden was born in Westfield, Massachusetts...
1860 - Scaphites whitfieldi † Cobban 1951b